Interesting article on climate change

Blitzkrieger

http://www.timesonline.co.uk/tol/news/uk/article1363818.ece

luapenak

http://physicsweb.org/articles/world/20/2/2/1
This article is interesting in the same way as the one above.
Even if you do agree that climate change is happening, it isn't very likely we will stop or delay it by a significant amount of time.

Lennoxschips

Changes in solar output are taken into account by climate scientists.

piraka

Lennoxschips wrote:

Changes in solar output are taken into account by climate scientists.

Where is solar output taken into account?

Lennoxschips

In the climate models used for climate predictions. There was a famous experiment where a climate model was run twice for period covering the last 200 our so years. In the first run only natural variations where included, such as changes in solar output, volcanic activity etc. In the second run the same natural variations were included, as well as increased greenhouse gases.

Both models replicated the temperature of the earth up until the 20th century, but only the one with greenhouse gases included was accurate from the 20th century onwards. The one without greenhouse gases said it should be much cooler now.

Variations in solar output are definitely taken into account, despite the author of the article in the first post, who has no background in climate science, accusing of otherwise.

Nobody has ever denied that solar variation doesn't affect climate on the timescales being discussed, it's just that the effects of man made greenhouse gases dwarf those effects at this moment in time. Sure, we've had a Little Ice Age and a Medieval Warm Period in the past 1,000 years, but what we're experiencing now is way outside that natural variability.

Frankly I'm disappointed that the Times would publish such a column.

piraka

In order to have an accurate model there has to be a reasonable to good understanding of the parameters.

In the IPCC AR4 Summary for Policymakers, Figure SPM 2 ( pdf ) the level of scientific undertanding for solar is defined as low. The only level of scienctific understanding given a high is for greenhouse gases and ozone. Surely this low understanding would have a bearing on the final projection of the model.

Lennoxschips

The understanding is low, that's why there is a large error bar. However, if you look at that chart you will see the tiny role that solar variation plays in the warming when compared to GHGs, even if you take the most extreme value on the error bar into account. Also, the figure states that GHGs play a very large role in global warming, and the understanding is rated as High, with a small error percentage bar.

By the way, the experiment I was referring to is on page 18 of that link. You should have a look at it. These models have been quite accurate at simulating observed past temperatures.

Richard Linzen, the guy from luapenak's post, offered to take bets that the Earth would be cooler in 2024 than it is now. However, he'd only take bets if you offered him odds of 50-1. Chancer.

Capt'n Midnight

When you have increased solar output there is more water evaporated off the oceans (and land). This increases cloud cover. White clouds reflect some of the extra heat.

This is one reason why increased solar output doesn't have as large effect on temperature as you might expect, also it's harder to predict the effect because you have to work out the cloud cover too.

Though it's a bit more complex in the real world since the increased UV light affects the ratio of DMS released by algae and that which gets in to the atmosphere where it acts as nucleation sites for cloud formation.

Keeks

While sea-ice has diminished in the Arctic since 1978, it has grown by 8% in the Southern Ocean.

“Why is east Antarctica getting colder?

Global warming is a sensitive issue. But the question is do we really know enough to be making decisions that have huge impacts on peoples lives.

I've just taken a couple of quotes from the OPs article above. If this is true it poses more questions. Like who is telling the truth?

At the moment it is political incorrect to say the Global warming is not caused by anthropogenic sources. But I have a feeling that this is about to change. And most of these studies wont be tainted by "big oils" money.

What the problem is, is simple. Enough is not known about how our climate works. An example of this is back in 97/98 the big buzz was EL Nino being a new phenomenon and now not a sausage. It turned out its being here forever.

whether global warming is caused by anthropogenic of natural causes, i cant answer that question. But I have a big problem at the moment how it is being used as a political tool. The IPCC report in 2001, its executive summary was re-written 3 times. The reason being was to "Toughen up" the language for Policy makers. Why would you have to do that?

The only reason I can think of is that if the report says there is nothing wrong then all funding will stop.

A bit cynical i know but nobody can deny that Global warming has become "big business" and now consumes a large aspect of society.

Is that what its all about now?

Lennoxschips

The IPCC report is a collaboration between scientists and governments. The bickering is about how tough the language should be. The scientists wanted "99%" certainty but the governments wanted to say there was less certainty. The end product was "90%" certainty. There is always negotiations on the language, it wasn't to "toughen up" the language per se. I don't understand what you are trying to say about El Nino.

“Why is east Antarctica getting colder?"

The Times columnist tries to act as if Antarctic cooling is unexpected. It is a local effect - the Earth does not heat uniformly - and it was predicted by climate models of the IPCC in 2001, six years ago:

For the change in annual mean surface air temperature in the various cases, the model experiments show the familiar pattern documented in the SAR with a maximum warming in the high latitudes of the Northern Hemisphere and a minimum in the Southern Ocean (due to ocean heat uptake)

There is a delay in Antarctic warming when compared to the rest of the world due to it being somewhat separated from global circulation by the Southern Ocean. The Southern Ocean acts as a buffer around Antarctica, absorbing heat - for the moment. However, the Antarctic is predicted to warm as well, eventually, once the warming kicks in there too as the Southern Ocean continues to warm up. It's just delayed. Once that starts heating up you'll have a nasty feedback effect going on in the Antarctic as the ice melts. We should be happy that it hasn't started warming there yet, it gives us time to do something now.

Blitzkrieger

Keeks wrote:

At the moment it is political incorrect to say the Global warming is not caused by anthropogenic sources. But I have a feeling that this is about to change. And most of these studies wont be tainted by "big oils" money.

Lennoxschips wrote:

Frankly I'm disappointed that the Times would publish such a column.

This is mostly why I posted the link. How can you be disappointed that the Times is attempting balanced journalism? My official opinion on global warming is "I don't know". I think we see far too much extreme opinion from both sides, but the hate that rabid enviormentalists try to inspire against people who don't agree with them makes me question their arguments.

Lennoxschips

It's not balanced journalism, it's a case of bad journalism. There is no debate on climate science really, 99.9% of climate scientists agree with the global warming theory. It's not a case of scare mongering rabid environmentalists, it's accepted and exhaustive worldwide research opinion.

The guy who wrote that column is not a climate scientist, he's a producer of science docus for television. And he was an editor for New Scientist between 1962 and 1966. Climate science is probably one of the few disciplines where people from complete other fields come along and publicly criticise things, mostly for political reasons. How often do you hear of cancer researchers getting criticised by TV producers in newspaper columns?

"While sea-ice has diminished in the Arctic since 1978, it has grown by 8% in the Southern Ocean."

Once again, he's using this as an argument, yet if he had read the 2001 IPCC report, he'd see that warming in the Antarctic was predicted to lag behind that of the rest of the world. Lazy journalism.

"The best measurements of global air temperatures come from American weather satellites, and they show wobbles but no overall change since 1999."

I can't believe that somebody use a period between 1999 and 2006 to argue their point, but, hey, look for yourself.



Do you see what he describes? It's lazy journalism.

Keeks

What does the graph show?

When i look at it i see two distinct warming periods. Period 1 from 1910-1940 and Period 2 from 1970-2000 and a small drop/leveling of temp in between. Now to me the rate on increase in both warming periods is about the same, no major difference.

Now it is widely known that CO2 emissions was far greater in period 2 than period 1.

So what initially caused the temp to increase in period 1 and why hasn't it increase by a much bigger rate in period 2?

You are going around accusing people of bad journalism and yet show a graph temperature data of the last 150 years to prove global warming?

That is bad science!

Even with all the studies we know little about how our climate truly works. And what we need to do is examine data, but not be hasty in drawing conclusions from it. What you have shown is a 150 year period. It is widely believed that climate follows a 1500 year cycle of going from hot to cold and back to hot again. Annual temperatures can vary between 5-8oC between these hot and cold periods.

This has been happening since the last ice age somewhere between 10000-18000 years ago depend on the report you read. Some scientists believe that we are actually overdue an ice age. since ans ice age occurs every 12000-15000 years again depending on the report you read.

Before every ice age there is a natural warming. Some scientist say that this is the start of the next ice age.

Some scientist call these guys mad.....but who knows since there is no debate on climate science.

lostexpectation

Keeks wrote:

What does the graph show?

Some scientist call these guys mad.....but who knows since there is no debate on climate science.

did you get that last line from luntz? no debate they're been debating it the last 50 years

i heard this guy on bbc R5 last night the interviewer never challenge him on teh antartic thing re the obvious point that some areas will get colder and some warmer for the next while

Lennoxschips

Keeks wrote:

You are going around accusing people of bad journalism and yet show a graph temperature data of the last 150 years to prove global warming?

That is bad science!

Yes, that would be bad science, but I did not show that graph to prove global warming. If you read the post you would see that I showed that graph to reference to the 1999-2005 period, a period the author of the article claimed proved that the Earth had stopped warming. I'm sure you'd agree, if using a 150 year period to prove something is bad, then using a six year period is even worse.

This has been happening since the last ice age somewhere between 10000-18000 years ago depend on the report you read. Some scientists believe that we are actually overdue an ice age. since ans ice age occurs every 12000-15000 years again depending on the report you read.

Ice Ages are dependent on the Earth's orbit around the sun. (This is known as Milankovitch theory) We are "overdue" an Ice Age if you assume the patterns of the past continue into the future, but that is not necessarily the case. Astrophysicists can accurately predict the Earth's orbit around the sun for many thousands of years into the future and according to a paper by one of the leading people in this field the current interglacial could last another 50,000 years. (http://www.sciencemag.org/cgi/content/full/297/5585/1287)

But Ice Ages / interglacials are things that happen on the very long term, outlasting entire civilisations. CO2 is causing warming now, on a human timescale.

silverharp

A couple of observations I have come across (not my own) if anyone would like to comment on them

It’s almost impossible to get funding for research that disputes the current theory

Scientists in the 1970’s were worried about global cooling and were proved wrong, why will they be any more correct this time

Lennoxschips

It’s almost impossible to get funding for research that disputes the current theory

There are quite a few oil companies willing to pay very good money to people who are willing to take shots at the current theory.

Scientists in the 1970’s were worried about global cooling and were proved wrong, why will they be any more correct this time

The cycles of the ice ages had been discovered then, and scientists were wondering how long it would be untill the next ice age begins. There were a couple of newspaper articles that blew everything out of proportion. Of course, Karl Rove uses it as a talking point nowadays.

Scientists have been going on about global warming longer than you think. Here's a film from 1958.

Dara Robinson

Blitzkrieger wrote:

http://www.timesonline.co.uk/tol/news/uk/article1363818.ece

I'll give it to you that what he is getting at is very possible but the whole point of "global warming" is the extreem weather. All the changes we have had in the last 100 years and no one can really say that our industrial age has not affected this in a positive way

Dara Robinson

Check this out, I just stumbled across this article and 40 min program by a Canadian prime time program

http://www.cbc.ca/fifth/denialmachine/index.html

Scary quote from one of the so called climate "scientist" featured on the vid "they supply usefull information to me, they send me things on the Canadian press that I cant get any where else" - He was talking about a PR firm funded by Exxon. Please tell me how a PR company, that just happens to be funded by the single largest oil corporation in the world, can supply "usefull information" to an impartial scientist regarding Global warming issues??????

jawlie

According to the Massachusets Institute of Technology, the world is imperceptibly warmer now than it was 100 years ago, and cooler than it was in the Middle Ages.

To suggest there is "no debate" about the consensus reached by those climatologists who believe that global warming is the result of increased CO2 & water vapour emissions, is simply to mislead. Even if it looks likely, there should be vigorous and probing debate.

There are many respected climatologists who do not concur, and it is interesting that those who do not concur are often the butt of personal and professional abuse, as can be seen in this thread also. ( They are probably in the pay of oil companies etc etc).

How about Heinz Wanner? How about Anders Moberg? How about all the other respected climatologists who do not agree?

How about Al Gore? Is he simply a politician seeking publicity? Or is he someone with special insight into it all? http://article.nationalreview.com/?q=YmFiZDAyMWFhMGIxNTgwNGIyMjVkZjQ4OGFiZjFlNjc

We should look at all the evidence with an open mind, and not fall into the intelligence trap, as described by Edward de Bono, and merely decide for one side or another, and then rush to find evidence with which we agree, and ignore or rubbish evidence with we do not agree.

Lennoxschips

there should be vigorous and probing debate.

That is exactly what the Intergovernmental Panel on Climate Change (IPCC) is for. If you want to get something into the IPCC report then it has to be scientifically watertight and stand up to vigorous and probing criticism. The IPCC is reviewed and approved by all UN member governments, including even the United States and Australia. The IPCC report is not some environmentalist propaganda, it is poured over and approved by scientists and governments alike.

There were much graver predictions that some people wanted to include in the IPCC report, which predicted a much higher rate of warming and sealevel rise, but these weren't included because they weren't perceived to stand up to vigorous and probing criticism. Similarly, the critics of anthropogenic greenhouse warming can't get their stuff into the IPCC reports for the same reason.

piraka

Lennoxschips wrote:

That is exactly what the Intergovernmental Panel on Climate Change (IPCC) is for. If you want to get something into the IPCC report then it has to be scientifically watertight and stand up to vigorous and probing criticism. The IPCC is reviewed and approved by all UN member governments, including even the United States and Australia. The IPCC report is not some environmentalist propaganda, it is poured over and approved by scientists and governments alike.

Then, why have eminent scienstists resigned from review panels.

Lennoxschips

There was a guy who resigned because he thought that the link between global warming and increased hurricanes was overstated. He did agree with global warming in itself though, let's not forget that. The new IPCC doesn't state any quantitative increase in hurricanes due to global warming, so this guy may have resigned a bit prematurely.

I can't think of anyone else at the moment.

piraka

Lennoxschips wrote:

There was a guy who resigned because he thought that the link between global warming and increased hurricanes was overstated. He did agree with global warming in itself though, let's not forget that. The new IPCC doesn't state any quantitative increase in hurricanes due to global warming, so this guy may have resigned a bit prematurely.

I can't think of anyone else at the moment.

Landsea,

" I am withdrawing because I have come to view the part of the IPCC to which my expertise is relevant as having become politicized. In addition, when I have raised my concerns to the IPCC leadership, their response was simply to dismiss my concerns."

http://www.lavoisier.com.au/papers/articles/landsea.html

Did Roger Pielke Sr resign? Lindzen did for certain.

piraka

Lennoxschips wrote:

In the climate models used for climate predictions. There was a famous experiment where a climate model was run twice for period covering the last 200 our so years. In the first run only natural variations where included, such as changes in solar output, volcanic activity etc. In the second run the same natural variations were included, as well as increased greenhouse gases.

Both models replicated the temperature of the earth up until the 20th century, but only the one with greenhouse gases included was accurate from the 20th century onwards. The one without greenhouse gases said it should be much cooler now.

Variations in solar output are definitely taken into account, despite the author of the article in the first post, who has no background in climate science, accusing of otherwise.

Nobody has ever denied that solar variation doesn't affect climate on the timescales being discussed, it's just that the effects of man made greenhouse gases dwarf those effects at this moment in time. Sure, we've had a Little Ice Age and a Medieval Warm Period in the past 1,000 years, but what we're experiencing now is way outside that natural variability.

Frankly I'm disappointed that the Times would publish such a column.

This reminds me of a famous experiment that Lorenz did many years ago in which the climate model that he repeated, after he removed a few decimals, diverged from the original, after a time interval.

The unusual positive index of the North Atlantic Oscillation observed over the past number of years, which is a major influence of climate over Eurasia, has not been successfully modeled by climate models.

Lennoxschips

He removed a few decimals? It diverged? Could you be more specific? Do you have a link to the study?

I'm not the greatest fan of the IPCC either, I think it's too politicised also, but because it doesn't emphasis the potential effects of climate change enough. Too many governments are meddling with it and weakening the language. But the stuff that does get in there is scientifically pretty damn watertight.

The unusual positive index of the North Atlantic Oscillation observed over the past number of years, which is a major influence of climate over Eurasia, has not been successfully modeled by climate models.

That's like saying that long term climate climate models don't predict that it might rain tomorrow. They have NAO cycles in there, they're just not accurate year on year. But long term climate models are used to predict exactly that, the long term. We want to know what it might be like in 2040, 2060, 2100...

It's also important to know that NAO is an internal climate variability mechanism, controlling how heat is redistributed throughout the planet. However, the overall heat of the planet will still increase with increased greenhouse gases. NAO only controls how this heat is redistributed.

piraka

Lennoxschips wrote:

He removed a few decimals? It diverged? Could you be more specific? Do you have a link to the study?

I was just quoting from a very early read of a book, Chaos by James Gleick (Chapter : Butterfly Effect, pg 16). The models then would have been very crude. They are now refined and more accurate, though still not complete.

That's like saying that long term climate climate models don't predict that it might rain tomorrow. They have NAO cycles in there, they're just not accurate year on year. But long term climate models are used to predict exactly that, the long term. We want to know what it might be like in 2040, 2060, 2100...

Yes the NAO is modeled. The point that I am making is that the models do not agree with actual records and observations. If there is no agreement with observation how can the models be accurate, especially projecting climate 40, 50, 100 years hence.

Lennoxschips

Well they agree very well with the global temperature record and observations, as I said. And that's what we're interested in.

piraka

Lennoxschips wrote:

Well they agree very well with the global temperature record and observations, as I said. And that's what we're interested in.

There appears to be issues with the observed global temperature records.

http://blue.atmos.colostate.edu/publications/pdf/R-321.pdf

Capt'n Midnight

Text on http://en.wikipedia.org/wiki/Image:Radiative-forcings.svg


Note the size of the error bars



This link below shows the change since 1750 and the level of understanding of the mechanisms
http://upload.wikimedia.org/wikipedia/en/thumb/b/bb/Radiative-forcings.svg/600px-Radiative-forcings.svg.png

Another effect is the black soot from diesel exhausts - but this should reduce as engines, cyclonic and other filters and fuel improve.

piraka

Lennoxschips wrote:

The understanding is low, that's why there is a large error bar. However, if you look at that chart you will see the tiny role that solar variation plays in the warming when compared to GHGs, even if you take the most extreme value on the error bar into account. Also, the figure states that GHGs play a very large role in global warming, and the understanding is rated as High, with a small error percentage bar.

Capt&#8217 wrote: »

Note the size of the error bars

Note IPCC 2001 Synthesis Report WGI Technical Summary pg 37 Figure 9 defines the vertical bar as having no statistical basis.

http://www.grida.no/climate/ipcc_tar/vol4/english/pdf/wg1ts.pdf

The vertical line about the rectangular bar with “x” delimiters indicates an estimate of the uncertainty range, for the most part guided by the spread in the published values of the forcing. A vertical line without a rectangular bar and with “o” delimiters denotes a forcing for which no central estimate can be given owing to large uncertainties.

The uncertainty range specified here has no statistical basis and therefore differs from the use of the term elsewhere in this document. A “level of scientific understanding” index is accorded to each forcing, with high, medium, low and very low levels, respectively. This represents the subjective judgement about the reliability of the forcing estimate, involving factors such as the assumptions necessary to evaluate the forcing, the degree of knowledge of the physical/chemical mechanisms determining the forcing, and the uncertainties surrounding the quantitative estimate of the forcing (see Table 6.12).]

The IPCC Climate Change 2001: The Scientific Basis, Chapter 6 : Radiative Forcing of Climate Change, pg 321 footnote

The “uncertainty range” for the global mean estimates of the various forcings in this chapter is guided, for the most part, by the spread in the published estimates. It is not statistically based and differs in this respect from the manner “uncertainty range” is treated elsewhere in this document.

http://www.grida.no/climate/ipcc_tar/wg1/pdf/TAR-06.PDF

Lennoxschips

The large amount of net warming caused by greenhouse gases is listed with a "High" understanding.

jawlie

Scientists who questioned mankind's impact on climate change have received death threats and claim to have been shunned by the scientific community.

They say the debate on global warming has been "hijacked" by a powerful alliance of politicians, scientists and environmentalists who have stifled all questioning about the true environmental impact of carbon dioxide emissions.

Timothy Ball, a former climatology professor at the University of Winnipeg in Canada, has received five deaths threats by email since raising concerns about the degree to which man was affecting climate change.
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One of the emails warned that, if he continued to speak out, he would not live to see further global warming.

"Western governments have pumped billions of dollars into careers and institutes and they feel threatened," said the professor.

"I can tolerate being called a sceptic because all scientists should be sceptics, but then they started calling us deniers, with all the connotations of the Holocaust. That is an obscenity. It has got really nasty and personal."

Last week, Professor Ball appeared in The Great Global Warming Swindle, a Channel 4 documentary in which several scientists claimed the theory of man-made global warming had become a "religion", forcing alternative explanations to be ignored.

Richard Lindzen, the professor of Atmospheric Science at Massachusetts Institute of Technology - who also appeared on the documentary - recently claimed: "Scientists who dissent from the alarmism have seen their funds disappear, their work derided, and themselves labelled as industry stooges.

"Consequently, lies about climate change gain credence even when they fly in the face of the science."

Dr Myles Allen, from Oxford University, agreed. He said: "The Green movement has hijacked the issue of climate change. It is ludicrous to suggest the only way to deal with the problem is to start micro managing everyone, which is what environmentalists seem to want to do."

Nigel Calder, a former editor of New Scientist, said: "Governments are trying to achieve unanimity by stifling any scientist who disagrees. Einstein could not have got funding under the present system."

http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/03/11/ngreen211.xml

Lennoxschips

Obviously it's out of order to issue death threats to anyone, but unfortunately there will always be morons in the world.

Interesting though they don't like being called deniers and then go and call other people liars. But there you go.

I don't think they can complain about not getting their place in the spotlight. I can't seem to open a newspaper or magazine nowadays without reading about Richard Lindzen of MIT and former New Scientist editor Nigel Calder.

Had to chuckle at the Einstein remark though.

Keeks

Lennoxschips wrote:

Had to chuckle at the Einstein remark though.

But it is a valid point. It is extremely hard, if not impossible to get funding for any study that doesn't involve something to do with global warming

Take a hypothetical situation:

If i wanted to do a study with on penguins in the antarctic which of these two proposals would get the funding

1.) I want to study Penguins mating habits in the antarctic

2.) I want to study the effects of global warming on the Penguins mating habits in the antarctic

Which is more likely to get the funding even though both will turn out the same results

jawlie

Lennoxchips answer is interesting insofar as it wants to make light of the thrust of the point of the article in what appears to be a patronising fashion.

I am not a scientist, but realise that there are respectable arguments which conflict with the greenhouse gases argument. The job of any scientist is to be sceptical and lennoxchips apparent position is to agree with those who posit the greenhous gases position, and ignore or rubbish anyone who disagrees with it, or even anyone who produces evidence which seems to not agree with it.

It is as impossible to argue logically with such people, as it is with a Nun about christianity, as both are based on a belief in dogma and orthodoxy, as opposed to rational and rigorous examination of the facts.

The sad fact is that some of the exponents of the greenhouse gas theory are self righteous, intolerant and inherently totalitarian. Because of what they see as the indubitable rightness, and the absolute moral transcendence, of their cause, they can justify demonising anyone who criticises or dissents from it. Hence the MacCarthy like persecution of those who question or produce evidence which seems to not fit with it, up to and including death threats.

Greenhouse gas theory is now big business and is welcomed by big business as yet another means of driving smaller competitors out of business and erecting another barrier to new entrants to their business. Just as they welcomed the health n'safety brigade who have helped them to to this also.

The greenhouse gas theory is just that, a theory.

Lennoxschips

Excuse me, I've engaged in a very factual debate here and on other threads, I think you are being disingenuous.

I'd love to argue with the climate facts in the telegraph piece, but there are none. Nor are they any facts in your reply above. Just empty words and accusations.

bonkey

jawlie wrote:

The greenhouse gas theory is just that, a theory.

There is no higher standard in science to reach than the status of theory.

piraka

bonkey wrote:

There is no higher standard in science to reach than the status of theory.

Proving the Theory?

Lennoxschips

Is grass green?

piraka

Lennoxschips wrote:

Is grass green?

Grass is green because it is envious of trees which are much taller and don't get stepped on like grass does.

Trees don't get mowed every week in the summertime and sprayed with Weedol.

jawlie

Lennoxschips wrote:

Excuse me, I've engaged in a very factual debate here and on other threads, I think you are being disingenuous.

I'd love to argue with the climate facts in the telegraph piece, but there are none. Nor are they any facts in your reply above. Just empty words and accusations.

There seems little point in arguing with you as your position, as I have already said, appears to be similar to that of a nun on the topic of christianity. I am open to being persuaded either way and recognise that there are good arguments on either side, being made by respected scientists, again on either side. Your position seems to be that you have made up your mind conclusively that its all the fault of greenhouse gases and don't seem to be open to evidence which might suggest otherwise.

I'm not saying you are wrong and maybe you are right. But then again maybe not. Scientists, from Gallileo's time onwards, (and probably before) so often get it wrong, and to swallow hook line and sinker what they say, and dismiss evidence to the contrary, does not seem an intelligent stance.

Lennoxschips

Once again, I'm not doing that at all. I'm actually open to debating any other theories regarding climate change. It's not my fault that they don't appear to hold water!

You seem to have made up your mind on me anyway.

bonkey

piraka wrote:

Proving the Theory?

You prove mathematical theorems. You don't prove scientific theories. Its a common misuse of terminology, but when it comes to scientific models being challenged and the garnering of public support for one side or the other, it is important to realise that "just a theory" in science is saying more "just as good as it gets" and less "just some idea".

Capt'n Midnight

By definition you can't prove a theroy ( if it's provable it's not a therory )

But to be a good theory it has to be disprovable, so that it makes predictions ( or whats the use ) that can be checked, rather than just be a best match for the existing evidence.

Lennoxschips

The predictions made by the IPCC in 1990 for the middle of this decade have been borne out...

jawlie

Lennoxschips wrote:

The predictions made by the IPCC in 1990 for the middle of this decade have been borne out...[/QUOTE

That sounds like nun's logic. We are here, therefore God must exist. Its getting warmer, therefore the reasons for that must be as the IPCC say.

Hmmm.

bonkey

jawlie wrote:

That sounds like nun's logic.

No, it doesn't.

I sounds like the model-based predictions were borne out, suggesting that there can be some degree of confidence in the model. It shows that the model has successfully passed a falsifiability test - the fundamental benchmark of scientific evaluation.

Hmmm.

Hmmm, indeed.

Just how often does a model's predictions need to match observation before you start considering that it may be a good predictive model? Thats a serious question, incidentally - where do you set the bar in terms of a model becoming acceptable?

Or - dare I suggest it - does the acceptability of the model depend more on the appeal of what it says rather than the accuracy of its predictions?

jawlie

I don't think anyone seriously doubts that the world is going through a period of warming, and no doubt some parts of many theories may well be correct. I am more interested to know how the flaws in the models can be explained. For instance, there are numerous examples showing that the world has been considerably warmer for significant periods historically. Schniedejoch in the swiss alps springs to mind. Also, the Oronteus Finaeus Map of 1532 show the antarctic ice free and accurately mapped. These are two examples which show the world was considerably hotter than it is today.

Who is to say that we are not warming up for the same reasons as before?

I am old enough to remember that the scientific "consensus" in the 1970's and 1980's was that we were on the verge of another ice age, and people were ridiculed then for suggesting this was nonsense, just as they are now ridiculed, and worse, for questioning the current orthodoxy.

Can you explain how come the earth has been so much hotter for periods in the past?

Lennoxschips

The Antarctic wasn't ice free in 1532. It hasn't been ice free for over 25 million years.

I am old enough to remember that the scientific "consensus" in the 1970's and 1980's was that we were on the verge of another ice age, and people were ridiculed then for suggesting this was nonsense, just as they are now ridiculed, and worse, for questioning the current orthodoxy.

This isnt' true at all, these are all recycled talking points. There was never any consensus for any of this and nobody was ridiculed for suggesting otherwise, as the whole thing was still work in progress. Global warming has been known about for years. Here's a children's documentary from 1958.

Can you explain how come the earth has been so much hotter for periods in the past?

Yes I can, and have on other threads.

jawlie

Lennoxschips wrote:

The Antarctic wasn't ice free in 1532. It hasn't been ice free for over 25 million years.

This isnt' true at all, these are all recycled talking points. There was never any consensus for any of this and nobody was ridiculed for suggesting otherwise, as the whole thing was still work in progress. Global warming has been known about for years. Here's a children's documentary from 1958.

You claim the antarctic has not been ice free for 25 million years, yet give no explanation as to how the land which is now under the ice of the antarctic was mapped accurately in 1532.

I'm not sure if you are saying that I am lying when I remember being told, ad nauseum, all over the media of the great threat of another ice age coming, or whether you are saying my memory is faulty. Either way, you are wrong.

To produce a "childrens documentary" from 1958 as evidence would appear to says more about the rigour with which you select what you consider to be evidence.